Recent research findings have shown strong associations between participation in sports and reduced sexual risk-taking, especially among adolescent girls. The present R21 application will extend this research to explore the effects of sports and other extracurricular activities on substance use and other risky behaviors among female and male adolescents. Cost-effective, secondary data analysis is proposed using two large data sets. The Family and Adolescent Study, a six-year longitudinal study of Western New York adolescents and their families (N=699), includes self-report data on alcohol, tobacco, marijuana and other substance use, sexual activity, and a variety of delinquent behaviors, as well as questions regarding recent participation in extracurricular activities. The 1997 school-based Youth Risk Behavior Survey (YRBS), generated by the Centers for Disease Control and Prevention, is a nationally representative cross-sectional survey of priority health-risk behaviors in American high school students (N=l 6,262). The YRBS includes data on tobacco, alcohol, marijuana, steroids, and other illicit drug use, sexual activity, and behaviors resulting in unintentional and intentional injuries (e.g., drunk driving, fighting, weapons carrying), as well as questions on athletic participation. Both sources of data oversample racial/ethnic minority populations, facilitating race-specific analysis. Specific aims of the study include determination of the nature of the relationships between sports and other specific extracurricular activities and substance use and other risky adolescent behaviors. Gender and racial/ethnic differences in these relationships will be determined. This research will also serve as a basis for the development of a theory- driven R01 proposal examining factors associated with gender-specific sports participation and substance use. This research has the overall aim of establishing more effective prevention and intervention strategies for reducing adolescent substance use and other related risk behaviors.